Shock-absorbing bicycle handlebar assembly

ABSTRACT

A bicycle handlebar assembly (25) for damping and reducing the shock to which a cyclist is normally exposed. The assembly includes a mounting block (256) attached to the head (12) of a bicycle front fork assembly. An upper linkage member (252) and a lower linkage member (254) that are parallel and spaced apart from each other are pivotally attached at their tail ends to the mounting block. A handlebar claim (258) for securing a set of handlebars (24) thereto is pivotally attached to the front ends of the upper and lower linkage members. The static angle of the linkage members may be adjusted by movement of an eccentric bearing pin. A damping element is disposed against one of the linkage members for slowing the downward movement of the linkage members and serving as a sink for a downward force applied to the linkage members when the handlebars are urged downward. A spring element (268) may be the damping member.

RELATIONSHIP TO OTHER APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 08/045,984, filed Apr. 9, 1993, now U.S. Pat. No. 5,285,697,which in turn was a continuation-in-part of U.S. patent application Ser.No. 07/982,229 filed Nov. 25, 1992, now U.S. Pat. No. 5,253,544. The'229 application was a continuation of application Ser. No. 07/760,621filed Sep. 19, 1991, now abandoned. The '621 application was acontinuation-in-part of application Ser. No. 07/648,173 filed Jan. 30,1991, now abandoned.

FIELD OF THE INVENTION

This invention relates generally to an assembly for attaching handlebarsto a bicycle and, more particularly, to a shock-absorbing handlebarassembly that is capable of absorbing mechanical shock to which abicyclist is normally exposed.

BACKGROUND OF THE INVENTION

Bicycles have proved to be very efficient vehicles for converting humanenergy into mechanical energy in order to produce self-propelled motion.Despite their usefulness, many bicycles suffer from one problem that candampen the enthusiasm of the most ardent cyclist. The problem is thatbicycles are not very good shock absorbers. Consequently, many of thebumps and jolts that a bicycle is exposed to are transferred with littlereduction in frequency or amplitude to the cyclist. These shocks mustthen be absorbed by the cyclist's body, which, over time, may not beable to withstand their effects. Shock exposure is of special concern topersons who enjoy either "mountain" or "off-road" bicycling and topersons who enjoy distance bicycling. Mountain and off-road bicyclistsare exposed to a significant amount of shock because the surfaces onwhich they ride are quite uneven and, consequently, many of the terrainbumps are simply passed through the bicycle to the cyclist's limbs.Distance cyclists are subjected to mechanical vibrations, which, whileless intense than those to which off-road cyclists are exposed, can overtime cause portions of their bodies to ache and become numb.

One part of the bicycle through which vibrations are transferred to thecyclist is the handlebars. In most bicycles, vertical motion caused bythe front wheel traveling over bumps or other uneven surfaces is onlymarginally attenuated by compression of the front tire. As a result, themotion is transferred through the front wheel fork assembly, through thestem of the assembly, through the handlebars attached to the stem, andfrom there into the hands and arms of the cyclist where it is absorbedby his/her joints. At the least, repeated exposure to this rapid up anddown motion can cause parts of one's body to go numb and serves only todetract from the pleasure of cycling. At the worst, this repeated shockcan induce individual pain or injury to the point where some individualssimply find it necessary to forgo bicycling.

There have been some attempts to provide shock-absorbing handlebars tominimize vibration transferred from bicycle to cyclist. These assemblieshave typically comprised providing a linkage that allows the handlebarsto pivot in an arc relative to a point on a line running through thefront fork assembly stem. These assemblies have often been provided withsome type of compressible member to damp the pivoting motion. Adisadvantage of these assemblies is that they expose the cyclist's handsand arms to a downward and rearward pivoting motion that produces awhole new set of strains on the cyclist's body. Also, since almost allcyclists ride with the back portions of their hands facing forward, thisinward and downward motion can be uncomfortable for the cyclist.Furthermore, because of these adverse effects of the pivoting motion,many of the assemblies are designed so that they allow the handlebars tohave only a limited degree of movement. Consequently, the amount ofvibration these assemblies are able to absorb is limited. Moreover, thedesign of many of these assemblies has made them unsuitable for use withtriathlon handlebars and other nonstandard handlebars, which are favoredby a growing number of cyclists. These assemblies also do not allow foradjustment of their static rise angle. Thus, the present assemblies haveproved to be of little value for reducing the vibrations to which agreat number of cyclists are exposed.

SUMMARY OF THE INVENTION

The invention is directed to a new and useful shock-absorbing handlebarassembly for reducing the front fork shock that bicyclists mustotherwise endure. The assembly of this invention includes a set ofhandlebars that are mounted to a bicycle so that they move along arelatively straight path and have a relatively long path of movement sothat the assembly, rather than the cyclist, bears the brunt of themechanical shock.

The assembly of this invention includes a pair of spaced upper and lowerlinkage members pivotally attached to a mounting block that is securedto the stem of the bicycle front fork assembly. A handlebar clamp forsecuring a set of handlebars thereto is pivotally attached to the otherend of the linkage members. A damping member that is in contact with atleast one of the linkage members is provided to resist downward movementof the linkage members. The damping member in most embodiments of theinvention also serves to restore the linkage members to their originalpositions upon the release of the downward force on the handlebars. Stopmembers, attached to one or both of the linkage members, limit theupward movement of the members and the handlebars.

In some preferred embodiments of this assembly, the damping membercomprises one or more elastomeric elements that are disposed between thelinkage members. In other preferred embodiments of the invention,springs that are mechanically linked to one or both of the linkagemembers serve as the damping members.

When a bicycle with this assembly is subjected to front wheel vibrationor shock, the cyclist's natural motion will cause him to push down onthe handlebars in normal fashion. The linkage members will, in turn, beforced to pivot to cause the handlebar clamp and the handlebar to movedownward in a substantially linear path. During the downward motion, thedamping member absorbs a portion of the downward force imposed upon theassembly to cushion and slow the downward movement of the handlebars.When the cyclist releases downward force on the handlebars, the dampingmember urges the linkage members upward so that the assembly returns toits initial position.

The handlebar assembly of this invention absorbs a significant amount ofthe front-end shock that results from the vertical movement to which abicycle is regularly exposed. Since the assembly, rather than thecyclist, absorbs the shock, the incidence of the cyclist's hands andarms stiffening from the adverse effect of this motion is reduced.

When this handlebar assembly is exposed to a shock-induced downwardmotion, the handlebars move in the same general orientation in which thecyclist's hands and arms move. In other words, the assembly allows thecyclist's body to move along the same path that it would naturally moveif the assembly were not present. Thus, the assembly serves to attenuatethe shock without causing the cyclist any unnatural or uncomfortablemovements.

A related advantage of the handlebar assembly of this invention is that,since it allows the cyclist to move in his natural path when exposed toshock, the range over which the handlebars are allowed to travel isrelatively long. This allows the assembly to absorb some of the evenlarger front-end shocks to which mountain and off-road bicyclists areexposed.

Moreover, in some embodiments of the invention the damping member mayactually consist of multiple damping elements. For example, there may betwo damping springs. Alternatively, there may be a spring and a pair ofdamping pads or gas shocks. An advantage of these embodiments of theinvention is that one of the damping elements can serve to damp thehigher frequency "road" vibrations while the other can serve to reduceexposure to low-frequency "bump" vibrations.

Other embodiments of this invention are provided with a lockout arm thatcan be connected between the upper and lower linkage members toselectively inhibit or block the shock-absorbing capabilities of thehandlebar assembly. This feature is useful for cyclists who, during thecourse of a particular ride, for example, when they are sprinting, maywish to block the shock-absorbing capabilities and import the maximumdownward force to the pedals. Then, when the assemblies ofshock-absorbing capabilities are desired, the lockout arm can bereleased to allow the linkage arms to pivot in order to take advantageof the assembly's shock-absorbing capabilities.

In still other embodiments of this invention, the rise angle of thelinkage members is adjustable such that the handlebar height can beadjusted. Preferably, the rise angle adjustability is provided by abearing pin having a pinhead eccentrically attached to a pin cylinder.The pin cylinder is coupled to the upper or lower linkage. By rotatingthe position of the pinhead within the head unit, the location of thepin cylinder, and also the rise angle, is changed. The pinhead includesa tapered outer surface engaged within a tapered bore in the head unitsuch that it does not easily rotate when tightened.

Also, the assembly of this invention is both lightweight and compact insize. Furthermore, the design of the assembly and the type of movementto which the handlebars are exposed to allow the assembly to be readilyused with triathlon-style and other unusual types of handlebars.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same becomesbetter understood by reference to the following detailed description,when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a first embodiment of the handlebarassembly constructed in accordance with this invention;

FIG. 2 is an exploded view of the handlebar assembly depicted in FIG. 1;

FIG. 3 is a side view, in partial cross section, of the handlebarassembly showing the assembly in a first static position and, in dashedlines, in a downward position;

FIG. 4 is a side view, in partial cross section, showing an alternativeembodiment of the handlebar assembly of this invention;

FIG. 5 is a side view showing, in partial cross section, a thirdembodiment of the handlebar assembly of this invention;

FIG. 6 is a plan view, in partial cross section, showing the handlebarassembly of FIG. 5;

FIG. 7 is a side view shown, in partial cross section, depicting how thehandlebar assembly of FIG. 5 can be adjusted, wherein one position ofthe assembly is shown in solid and the other in phantom;

FIG. 8 is a side view illustrating, in partial cross section, a fourthembodiment of the handlebar of this invention;

FIG. 9A is a plan view of the handlebar assembly of this inventionincluding a speedometer processing unit;

FIG. 9B is a side view, in partial cross section, of the speedometer ofFIG. 9A mounted on the handlebar assembly of FIG. 1;

FIG. 10 is an exploded perspective view of an alternative embodiment ofthis invention;

FIG. 11 is a partial cutaway side view of the embodiment of theinvention of FIG. 10;

FIG. 12 is a partial cutaway bottom view of the embodiment of theinvention of FIG. 10;

FIGS. 13A and 13B are partial cutaway views of a first fasteningassembly used in conjunction with the invention of FIG. 10;

FIG. 14 is an exploded perspective view of an alternative embodiment ofthis invention;

FIG. 15 is a partial cutaway side view of another embodiment of theinvention of FIG. 14;

FIG. 16 is a partial cutaway bottom view of the embodiment of theinvention of FIG. 14;

FIG. 17 is a partial cutaway view of the fastening assembly used inconjunction with the invention of FIG. 14;

FIG. 18 is an exploded perspective view of an alternative embodiment ofthis invention;

FIG. 18A is a cross-sectional view of the fastening assembly employed inthe embodiment of the invention of FIG. 18.

FIG. 19 is a partial cutaway side view of the embodiment of theinvention of FIG. 18;

FIG. 20 is a partial cutaway bottom view of the embodiment of theinvention of FIG. 18;

FIG. 21 is a side view of an alternative biasing assembly that can beincorporated into the various embodiments of this invention;

FIG. 22 is a side view of an alternative biasing assembly that can beincorporated into the various embodiments of this invention;

FIG. 23 is a side view of an alternative biasing assembly that can beincorporated into the various embodiments of this invention;

FIG. 24 is an exploded view of an alternative embodiment of thisinvention;

FIG. 25 is a cutaway view of the embodiment of the invention of FIG. 24;

FIG. 26 is a side view of another embodiment of the shock-absorbinghandlebar invention wherein the depicted version includes a lockout armthat can be used to selectively lockout the shock-absorbing capabilitiesof the assembly;

FIG. 27 is a cross-sectional view of the invention of FIG. 26;

FIG. 28 is an exploded view of the invention of FIG. 26;

FIG. 29 is an alternative version of the lockout arm that can beemployed with the shock-absorbing handlebar of FIG. 26;

FIG. 30 is partially exploded isometric view of an alternate embodimentof the invention having an adjustable rise;

FIG. 31 is a top, partial cutaway view of the bearing pins within thehead unit of the embodiment of FIG. 30; and

FIGS. 32A-C are side elevational views illustrating three positions ofthe handlebar clamp obtained by moving the bearing pin of the embodimentof FIG. 30.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a preferred embodiment of the handlebar assembly 10of this invention mounted to the stem 12 of a bicycle front forkassembly 14. The assembly includes a mounting block 16 that is securedto the head of the front fork assembly stem 12. A pair of upper andlower linkage members 18 and 20, respectively, are pivotally attached atone end to the mounting block 16. The linkage members 18 and 20 arearranged substantially parallel to each other and pivotally attached attheir second ends to a handlebar clamp 22 to which handlebars 24 aresecured. The linkage members 18 and 20 are spaced apart from each otherand an elastomeric block 26 is disposed in the space therebetween.

The handlebar assembly 10 is shown in greater detail in FIG. 2. Themounting block 16 consists of a metal block that is secured to the frontfork assembly stem 12. The upper and lower linkage members, 18 and 20,respectively, are generally rectangularly shaped pieces that haveperpendicularly extending flanges, 28 and 29, respectively, along theirlateral edges. The flanges 28 associated with the upper linkage member18 extend downward. The flanges 29 associated with the lower linkagemember 20 extend upward. Integral with both sets of flanges 28 and 29are mounting arms 30 that extend longitudinally outward from each of thefour comers of the linkage members 18 and 20. The linkage members 18 and20 are secured to the mounting block 16 by pivot pins 32. The pivot pins32 extend through openings 34 formed in the mounting arms 30 andopenings 36 formed in the mounting block 16.

One of the upper linkage member mounting arms 30 that abuts the mountingblock 16 is provided with a downwardly extending tab 37. The tab 37normally abuts a stop pin 38 that extends outward from the mountingblock 16. In a preferred embodiment of the invention, the stop pin 38 isin the form of an adjustable screw, and the head of the screw is in theform of a cam 39, so that the static angle of the assembly 10 relativeto the bicycle stem 12 can be selectively set.

The handlebar clamp 22 is in the form of a one-piece structure that hasa main body 40 with the basic shape of an elongated split O-ring. A pairof ears 42 formed with axially aligned openings 44 are affixed to thebody 40 on either side of the split. The ear openings 44 are dimensionedto accommodate a fastener, not illustrated, that serves to urge the endsof the body 40 together to securely compress the handlebars 24 in theclamp 22. A pair of pillars 48, each with a triangular profile andintegral with the body 40, secure the handlebar clamp 22 to the linkagemembers 18 and 20. Each pillar 48 is disposed between the free mountingarms 30 on the front end of an adjacent linkage member 18 or 20. Thepillars 48 are attached to the mounting arms 30 by pivot pins 32, whichextend through openings 34 in the mounting arms and openings 49 formedin the ears. Lower linkage member mounting arms 30, to which thehandlebar clamp 22 is attached, are each provided with a lip 50 thatextends inward perpendicularly from the mounting arm. The lower linkagemember mounting arm lips 50 serve to reinforce the mounting arms 30.

The elastomeric block 26 comprises a layer of elastomeric material 52that is sandwiched between two opposed metal plates 54. A suitableelastomeric material 52 that has the appropriate qualities, i.e., isresilient to the effects of both compression and shear, is a low- ormedium-durometer polyurethane, such as a polyurethane having a hardnessof between approximately 40 to 60 on the Shore Durometer A Scale. Theelastomeric layer can have a thickness of between approximately 0.5 to1.5 inches. The actual thickness will depend on factors such as thelocation of the pivots and the specific characteristics of theelastomeric material. Epoxy or other suitable adhesive is used to securethe metal plates 54 to the elastomeric material 52. The elastomericblock 26 is secured in place by the linkage member flanges 28 and 29, apair of ribs 56 that extend downward from upper linkage member 18, and apair of ribs 58 (shown in phantom in FIG. 3) that extend upward from thelower linkage member 20. The upper linkage member ribs 56 extend betweenthe adjacent upper linkage member flanges 28 and extend only as fardownward as the flanges. The lower linkage member ribs 58 similarlyextend between the adjacent lower linkage member flanges 29 and extendonly as far upward as the flanges.

When a bicycle is provided with the handlebar assembly 10 of thisinvention, the handlebars 24 are initially in the same position as whenthey are mounted with a conventional one-piece, static mounting arm.When a cyclist mounts the bicycle there may be some limited downwardmovement of the assembly 10, as represented by bidirectional arrow 60.The maximum movement of the assembly occurs when the bicycle passes overa bump or other surface roughness that forces the cyclist's upper bodydownward. When this happens, the cyclist pushes downward on thehandlebar 24, which, in turn, causes the linkage members 18 and 20 topivot downward and to be urged together, as is shown in dashed lines inFIG. 3. When the linkage members 18 and 20 are moved in this manner,each member pivots about the individual pivot point around which it issecured to the mounting block 16. As a result, the handlebar clamp 22and the handlebars 24 attached thereto travel downward, in an arc ofsuch a wide circumference that, for all intents and purposes, it isessentially a straight path.

During the downward motion of the assembly 10, the elastomeric block 26remains secured by the linkage member flanges 28 and 29 and the linkagemember ribs 56 and 58. Consequently, the elastomeric material 52 is bothcompressed by the inward movement of the linkage members 18 and 20 andis laterally deformed or sheared. The compression of the elastomericmaterial 52 serves as a sink for a portion of the downward force thecyclist imposes on the assembly 10 to slow downward movement of thelinkage members 18 and 20 and the other elements of the assembly 10. Theshearing of the elastomeric material further serves to decelerate thedownward motion of the linkage members 18 and 20 to further reduce theshock to which the cyclist is exposed. Also, during this movement of theassembly 10, the upper linkage member mounting arm tab 37 is pivotedrearward away from the stop pin 38.

When the cyclist's upper body returns to its initial position, thedownward force on the assembly 10 is released. The resilient propertiesof the elastomeric material 52 cause it to return to its initial shapeso that, in turn, the linkage members 18 and 20 are urged upward. Theupward motion of the linkage members 18 and 20 is then stopped by theupper linkage member tab 37 when it abuts the stop pin 38. The upwardmotion itself is actually damped by a portion of the return energy,which is absorbed by the elastomeric material 52 as it recovers from theshear state to its initial state. The absorption of this energy servesto damp the rate at which the assembly 10 returns to the initial,static, state.

The handlebar assembly 10 of this invention serves to absorb asignificant portion of the front-end shock to which a cyclist would beexposed. Whenever bumps or other surface discontinuities cause thecyclist's upper body to be pressed downward, the linkage members 18 and20 are forced downward. A portion of the downward force the cyclistimparts is then absorbed by the compression and lateral deformation ofthe elastomeric material 52. Thus, the downward movement of the linkagemembers 18 and 20 and the compression and deformation of the elastomericmaterial 52 serve to absorb a sizable portion of the mechanical shockthat would otherwise be absorbed by the cyclist's upper body.

Another advantage of the handlebar assembly 10 of this invention is thatthe parallel linkage members 18 and 20 move in a substantially linearand diagonal downward path when a force is imposed thereon. Thismovement is in line with the natural movement of the cyclist as hishands and arms travel downward. Furthermore, this movement does notcause the handlebars themselves to pivot inward. In other words, as thehandlebars 24 move downward, they do not rotate in the cyclist's hands.Thus, the movement of the handlebar assembly 10, including thehandlebars 24, is consistent with the natural movement of the cyclist soit does not impose any discomfort on the cyclist.

Furthermore, since the movement of the handlebar assembly 10 does notimpose any discomfort on the cyclist, the assembly is able to have arelatively long path of movement. This allows the assembly 10 to movedownward, and to continue to absorb shock even when large bumps forcethe cyclist into relatively large downward movements. This furtherenhances the ability of the assembly 10 to absorb shock that the cyclistwould otherwise feel.

Another feature of this invention is that the upper linkage member tab37 and the stop pin 38 cooperate to prevent the assembly 10 from movingupward beyond a certain, selected angle. This prevents the assembly 10from pivoting upward to the point where the linkage members 28 and 29meet. Consequently, when a cyclist pulls up on the handlebars 24, asfrequently happens when one pedals uphill, the assembly 10 limits theupward movement of the handlebars. This allows the cyclist to press offagainst the handlebars 24 to increase the mount of power that is appliedto the pedals. Moreover, the movement-stopping effect of the tab 37 andpin 38 prevents an excessive spring-back from handlebars 24, which couldotherwise further fatigue the cyclist's upper body.

Moreover, since the assembly 10 does not pivot inward significantly, itis well suited for use with triathlon handlebars and other nonstandardhandlebars that require the cyclist to ride with hands and armsoutstretched.

FIG. 4 illustrates an alternative handlebar assembly 70 constructedaccording to this invention. The assembly 70 includes an upper linkagemember and lower linkage member, 72 and 74, respectively, that arepivotally attached to a mounting block 75, which is secured to the headof a bicycle front fork assembly. The assembly 70 includes first andsecond elastomeric blocks 76 and 78, respectively, that are seated inthe space between the upper and lower linkage members 72 and 74. Thefirst elastomeric block 76 serves to damp the downward movement of theassembly 70 when the cyclist pushes down. The second elastomeric block78 serves to damp and stop the upward movement of the assembly after thecyclist releases the downward force. A handlebar clamp 80 identical tothe handlebar clamp 22 of the first embodiment of this invention is usedto secure the handlebar 24 to the other elements of assembly 70.

The linkage members 72 and 74 are relatively longer than linkage members16 and 18 of the first embodiment of the invention. Upper linkage member72 is formed with a pair of downwardly extending flanges 82 along itslateral edges. Lower linkage member 74 is formed with a pair of upwardlyextending flanges 84 along its lateral edges. The upper linkage member72 is formed with a first base plate 86 at its tail end and a secondbase plate 88 that is stepped down from the first base plate 86. Thelower linkage member 74 is formed with a base plate 90, shown inphantom, that is relatively shorter than the adjacent flanges 84 so thatthe flanges extend rearward from the base plate. Elastomeric blocks 76and 78 are seated between upper linkage member second base plate 88 andlower linkage member base plate 90.

Each linkage member flanges 82 and 84 is formed with a set of openings94 to facilitate mounting the linkage members 72 and 74 to the mountingblock 75 with pivot pins 96. The multiple openings 94 allow theadjustable mounting of the assembly 10 to the bicycle so that thecyclist can select how much forward of the front fork the handlebars 24are located. When this assembly 10 is mounted on the bicycle, themounting block 75 and head of the front fork assembly are located in thespace between the lower linkage member flanges 84.

The lower linkage member 74 is formed with a first upwardly extendingtongue 98 adjacent the tail edge of the base plate 90 and a secondupwardly extending tongue 100 adjacent the leading edge of the baseplate. The upper linkage member 72 has a downwardly extending tongue 102that is located in approximately the middle of the second plate 88. Thelower linkage member first tongue 98 and the upper linkage member tongue102, in combination with the adjacent linkage member base plates 88 and90, define the space in which the first elastomeric block 76 is seated.The lower linkage member second tongue 100 and the upper linkage membertongue 102, in combination with the adjacent linkage member base plates88 and 90, define the space in which the second elastomeric block isseated. The linkage member tongues are dimensioned so that the lowerlinkage tongues 98 and 100 partially overlap the upper member linkagetongue 102. The linkage member tongues are further dimensioned so thatthe tips of the lower linkage member tongues 98 and 100 are spaced fromthe adjacent upper linkage member plate 88 and the upper linkage membertongue 102 is spaced from the lower linkage member base plate 90. Thespacing is such that, when a downward force is imposed on the assembly10 and the linkage members 72 and 74 are urged together, the lowerlinkage member tongues 98 and 100 remain separated from the upperlinkage base plate 88 and the upper linkage member remains separatedfrom the lower linkage base plate 90.

The linkage member tongues are spaced from each other so that when theassembly 10 is in a static position, the lower linkage member secondtongue 100 and the upper linkage member tongue 102 compress or preloadthe second elastomeric block 78, while the lower linkage member firsttongue 98 and the upper linkage member tongue do not impose a similarload on the first elastomeric block 76.

When a bicycle equipped with handlebar assembly 70 is exposed to afront-end shock, the upper body of the cyclist will be forced downwardin the usual manner. The hands and arms of the cyclist will pressdownward on the handlebars 24 so as to causing the linkage members 72and 74 to pivot downward. As the linkage members 72 and 74 pivot, thelower linkage member first tongue 98 moves toward the upper linkagemember tongue 102 to compress the first elastomeric block 76therebetween. Simultaneously, the lower linkage member second tongue 100moves away from the upper linkage member tongue 102 so that the staticcompressive force on the second elastomeric block 78 is reduced. Afterthe cyclist releases the downward force on the assembly 70, theresilient qualities of the first elastomeric block 76 cause it toexpand, which, in turn, causes the assembly 70 to pivot upward. As theupper and lower linkage members, 72 and 74, respectively, pivot upward,the lower linkage member second tongue 100 and the upper linkage membertongue 102 move toward each other and recompress the second elastomericblock 78. This recompression of the second elastomeric block 78 servesto first slow and then stop the upward motion of the assembly 70 so thatthe assembly returns to its initial position.

The handlebar assembly 70 of this embodiment of the invention serves toreduce the shock to which a cyclist is exposed much like the assembly 10of the first embodiment. During the downward movement of the assembly70, the compression of the first elastomeric block 76 damps and absorbsmuch of the mechanical shock that would otherwise be transferred to thehands and arms of the cyclist. During the upward movement of theassembly 70, the recompression of the second elastomeric block 76 slowsthe movement of the linkage members 72 and 74 so that the cyclist is notexposed to any jolting motion during the return movement of the assembly70.

FIGS. 5-7 illustrate another handlebar assembly 110 of this invention.This assembly 110 includes an upper linkage member and a lower linkagemember, 112 and 114, respectively, that are pivotally attached to amounting block 116 secured to the head of the bicycle front forkassembly stem 12. A handlebar clamp 118, similar to the handlebar clamp22 (FIG. 1) of the first described embodiment of this invention, ispivotally attached to the front ends of the linkage members 112 and 114and is used to secure the handlebars 24 to the assembly 110. A leafspring 120, one end of which is mounted in a holder 122 attached to thestem of the front fork assembly, serves to damp and absorb the downwardmotion of the handlebars 24 and the linkage members 112 and 114. Anadjustable lug assembly 124 controls the static position of the linkagemembers 112 and 114 and stops the upward movement of the assembly 110.

The upper linkage member 112 is substantially identical in size andshape to the upper linkage member 18 of the first embodiment of theinvention (FIG. 1). The lower linkage member 114 has a base plate 126,located forward of the bicycle front fork assembly, and a pair offlanges 128 that extend perpendicularly downward from the lateral edgesof the base plate. The lower linkage member flanges 128 extend beyondthe tail end of the base plate 126 to function as mounting arms 130 thatare pivotally secured to the mounting block 116.

The holder 122 in which the leaf spring 120 is secured has a rectangularcross section and is secured to an exposed section of the bicycle frontfork assembly above the frame head tube by a metal strap or otherfastening member (fastening member not shown). The holder 122 is formedwith a top opening 123 from which the leaf spring 120 extends. In somepreferred embodiments of the invention, one or more threaded fasteners,not shown, may be used to secure the leaf spring 120 to the housing.

The leaf spring 120 is a single flexible band of metal. The metalforming the leaf spring may be wholly or partially covered with aplastic, such as Teflon, or material to inhibit corrosion and to reducefriction along the lower linkage member/spring interface. The leafspring 120 extends up from the holder 122 and curves forward so that theend of the spring is disposed against the undersurface of the lowerlinkage member base plate 126.

Lug assembly 124 includes a finger 134 that is mounted to a plasticcylinder 136 that, in turn, is affixed to a rotatable pin 138 mountedbetween the lower linkage member flanges 128 and the head of the frontfork assembly. Finger 134 is formed of reinforced rubber or materialwith similar resilient qualities and is relatively thick where fittedover the cylinder 136 and tapers to a relatively thin width at the enddistal therefrom. The distal end of the finger is formed with a concaveindentation 140 that conforms to the outer curvature of the adjacentfront fork assembly stem 12. The finger 134 is further formed with anopening 142 in which the cylinder 136 is secured by an adhesive.

The cylinder 136 is formed with an axially extending bore 144 in whichthe pin 138 is disposed. The bore 144 is dimensioned so that a coilspring 146 can be disposed therein around the pin 138. One end of thecylinder 136 is provided with an inwardly directed annular step 148 thatis dimensioned to abut the pin 138. Epoxy or other suitable adhesive maybe used to secure the cylinder 136 to the pin 138 around the inside ofthe step 148. A stop ting 150 is secured to the pin 138 adjacent the endof the cylinder 136 that does not include the step 148. A washer 152 isdisposed in the cylinder bore 144 between the end of the spring 146 andthe stop ring 150, such that the spring and the washer normally bias thestop ting away from the finger 134 and the cylinder 136.

The section of the pin 138 adjacent the cylinder step 148 is providedwith a head 154 adjacent the outer surface of the proximate lowerlinkage member flange 128. Attached to the pinhead 154 and designed torotate therewith is a star washer 156 with a set of circumferentiallyspaced-apart projections 158. The star washer projections 158 aredimensioned to be seated in complementary indentations 159 formed in theouter surface of the lower linkage member flange 128. (Only twoprojections and complementary indentations are shown.) The action of thespring 146 against the star washer 156 normally urges the star washerprojections 158 into the indentations so that the finger is secured inone fixed position.

When a cyclist asserts downward force on handlebars 24 of the assembly110 of this invention, the upper and lower linkage members 112 and 114,respectively, will pivot downward in a manner similar to the linkageassemblies of the previously described embodiments of the invention. Theleaf spring 120, which abuts the outer surface of the lower linkagemember base plate 126, resists the downward movement of the linkagemembers to both slow the downward movement and serve as a sink for thedownward force exerted against the assembly 110. As the assembly 110 isurged downward, the lug assembly 124 is rotated away from the bicyclefront fork stem such that the finger 134 is spaced away from the stem.When the cyclist stops exerting a downward force against the assembly110, the action of the leaf spring 120 against the lower linkage member114 pivots the assembly upward. The upward movement of the assembly 70is stopped by the action of the lug assembly finger 134 abutting theadjacent outer surface of the front fork stem 12.

The static position of the handlebar assembly 110 can be adjusted bychanging the relative setting of the lug assembly finger 134 against thefront fork stem. The lug assembly finger 134 setting is changed bypulling out on the lug assembly pinhead 154 so that the star washer 156is spaced away from the adjacent lower linkage member flangeindentations 159. The lug assembly pin 138 is then rotated so that thefinger 134 is directed downward. Using hand pressure the cyclist thenpositions the assembly 110 so that the handlebars 24 are in the desiredstatic position. After the static position of the handlebars 24 is set,the pin 138 is rotated upward until the indentation 140 and the distalend of the finger 134 abut the front fork stem. The pinhead 154 is thenreleased so that the spring 146 urges the star washer projections 158into the lower linkage member flange indentations 159. As illustrated bythe solid and phantom illustrations of the assembly in FIG. 7, thisallows the cyclist to adjust the relative height of the handlebars 24with a minimal amount of effort.

Another embodiment of a handlebar assembly 160 of this invention isillustrated in FIG. 8. The assembly 160 includes an upper linkage memberand a lower linkage member 162 and 164, respectively, that are pivotallymounted at their tail ends to a mounting block 166 attached to the headof the front fork assembly. A handlebar clamp 168 securing handlebars 24is adjustably attached to the upper and lower linkage members 162 and164, respectively, by a pair of telescoping slides 170 that are securedto the linkage members. A set of four elastomeric plugs 172 are disposedbetween the upper and lower linkage members 162 and 164, respectively. Athreaded rod 174 extends between the upper linkage member 162 and thelower linkage member 164. The free end of the rod 174 adjacent the lowerlinkage member is provided with an adjustably positionable catch 176 tolimit the upward movement of the assembly 160.

The upper linkage member 162 is formed with a rectangular base plate 178and a pair of sidewalls 180 that extend perpendicularly along thelateral edges of the base plate 178. Integral with and set below thefront end of the upper linkage base plate 178 is a slide plate 182. Theupper linkage member sidewalls 180 extend forward of the base plate 178around and above the lateral edges of the slide plate 182. The lowerlinkage member 164 is formed with a lower linkage member base plate 184and a pair of lower linkage member sidewalls 186 that extend laterallyalong the sides of the base plate. Integral with the lower linkagemember base plate 184 and stepped above the base plate is a lowerlinkage member slide plate 188. The lower linkage member sidewalls 186extend perpendicularly downward from the lateral edges of the lowerlinkage member slide plate 188. The upper and lower linkage membersidewalls 180 and 186, respectively, extend rearward from the associatedbase plates 178 and 184, respectively, to function as upper and lowermounting arms 190 and 192, respectively. The mounting arms 190 and 192are pivotally attached to the mounting block 166 using the previouslydescribed pivot pins.

The slides 170 are disposed against the slide plates such that one slideis positioned on top of the upper linkage member slide plate 182 and thesecond slide is positioned immediately below the lower linkage memberslide plate 188. Slides 170 are generally elongated bodies withsemicircular end sections and are formed with a number of openings 191such that, in combination with fastening elements 193 and openings 194formed in the front ends of the linkage member sidewalls 180 and 186,they can be selectively secured to the linkage members in eitherretracted, partially extended, or fully extended states. Within thefront ends of each slide 170 are a pair of spaced-apart mounting tabs196. The mounting tabs 196 are formed with openings 198 to facilitatepivotal connection of the pillars 200 on the handlebar clamp 168 to theslides by conventional means previously described.

The elastomeric plugs 172 comprise cylindrical plugs of elastomericmaterial, such as rubber or polyurethane, are approximately 0.5 to 0.75inch in diameter, and are approximately 0.5 to 1.5 inches in length. Theends of the plugs 172 may be seated in indentations formed in the upperand lower linkage member base plates, 178 and 184, respectively,indentations not shown. In the depicted embodiment of the invention therod 174 is welded or otherwise secured to the upper linkage member baseplate 178 between the elastomeric plugs 172 and has a threaded outersurface 204. The rod 174 extends through an opening 206 formed in thelower linkage member base plate 184 between the elastomeric plugs 172.The catch 176 is in the form of a complementary nut that is secured overthe free end of the rod 174 adjacent the outer surface of the lowerlinkage member base plate 184. One or more washers 208 formed ofelastomeric material are disposed over the rod between the outer surfaceof the lower linkage member base plate 184 and the catch 176.

When a downward force is imposed on handlebar assembly 160, the upperand lower linkage members 162 and 164, respectively, pivot downwardlyand are urged together. This movement causes the elastomeric plugs 172to be compressed between the upper and lower linkage member base plates178 and 184, respectively. Upon release of the downward force, theelastomeric qualities of the plugs 172 cause them to expand to urge thelinkage members 162 and 164 apart to force the assembly 160 upward. Theupward motion of the assembly 160 is stopped by the action of theelastomeric washers 208 abutting the outer surface of the lower linkagemember base plate 178. The elastomeric qualities of the washers 208serve to damp the actual sensation of movement of the assembly 160.

This assembly 160, like the other assembly 10, serves to damp and reducethe mechanical shock to which the cyclist would otherwise be exposed.Moreover, the slides 170 serve to allow the cyclist to adjust theposition of the handlebars 24 relative to the front fork stem.

FIGS. 9A and 9B depict another handlebar assembly 220 of this inventionthat includes a speedometer processing unit 222 integral therewith.According to this embodiment of the invention, an upper linkage member224 includes a base plate 226 against which an elastomeric block 26 isdisposed. The upper linkage member further includes a top plate 228 thatis integrally connected to the base plate 226 by a pair of sidewalls 230that extend therebetween. The top plate 228 is formed with a recess 231in which the speedometer processing unit 222 is disposed. Foam padding233 is provided on the surfaces of the top cover that defines the recess231 to cushion the speedometer unit 222. A cover 234 is provided overthe top plate recess 231 for securing the speedometer processing unit222 therein. The undersurface of the cover 234 is also provided withfoam padding 233 to further cushion the speedometer processing unit 222.

The cover 234 is formed with a first elongate rectangular opening 225through which a display of the speedometer processing unit 222 can beviewed and a set of smaller square openings 232 for actuating the keysof the speedometer processing unit 222. A small opening 236 is formed inone side of the upper linkage member sidewalls 230 so that a cable (notillustrated) can be connected between the speedometer sensor on thefront wheel to the processing unit 222. The cover 234 is secured to theupper linkage member top base plate 226 by nonstandard fasteners 240,for example, hex nuts.

An advantage of this embodiment of the invention is that, in addition toproviding a means for damping and absorbing mechanical shock to whichthe cyclist would otherwise be exposed, it provides a means for securinga speedometer processing unit 222 to a bicycle that is streamlined sothat it appears built-in, is aesthetically pleasing, and is relativelysecure from theft.

Another handlebar assembly 250 of this invention is depicted by FIG.10-12. Handlebar assembly 250 includes an upper linkage member 252 and alower linkage member 254, which are both pivotally connected at one endof a mounting block 256 attached to the head of the front fork stem 12.The opposite ends of the linkage members 252 and 254 are attached to ahandlebar clamp 258. A coil spring 260 extends between the tail end ofthe lower linkage member 254 and a stop assembly 262 mounted to thefront end of the upper linkage member 252.

Upper linkage member 252 is in the form of a hollow metal tube that isshaped to have a generally oval cross-sectional profile. A tubularsleeve 264 is attached to each end of the upper linkage member 252 toextend laterally across the linkage member. Lower linkage member 254 isformed from a channel-shaped piece of metal having two parallelsidewalls 266 that extend perpendicularly outward away from a basesection 267. The lower linkage member 254 is oriented so that theexposed edges of the sidewalls 266 are adjacent the upper linkage member252. The opposed sides of the lower linkage member define a spring space268 in which the spring 260 and stop assembly 262 are disposed. A pairof tubular sleeves 270 extend between the sidewalls adjacent the frontand rear edges of linkage base section 267. Sleeves 264 and 270 definepassageways (not identified) that extend laterally through the ends ofthe linkage members 252 and 254, respectively, to facilitate theinsertion of hardware for attaching the members to the other componentsof the assembly 250.

Mounting block 256 is formed with a cylindrical bore 272 to facilitatesecuring the mounting block to the head of the front fork stem 12.Fastening elements, not shown, may be used to secure the mounting block256 in place. A pair of flanges 274 extend forward from the rear half ofthe mounting block 256. The flanges 274 extend tangentially away fromsymmetrically opposed points located on either side of the longitudinalcenterline of the mounting block 256. The flanges 274 are each bent sothat the outermost sections thereof form a pair of parallel,spaced-apart tabs 276.

Linkage member 252 is pivotally secured to the mounting block tabs 276by a fastening assembly 278, as depicted in FIG. 13A. Fastening assembly278 includes a pair of ranged bushings 279 formed of Teflon(polytetrafluoroethylene plastic), bronze, or other suitablelow-friction material that extend through openings formed in the tabs276 and partially into the passageway defined by the adjacent upperlinkage member sleeve 264. Washers 284, formed of TEFLON™(polytetrafluoroethylene, a waxy, opaque material) or otherlow-friction, noncorrosive material, are disposed around each bushing279 between the adjacent surfaces of the tabs 276 and the sleeves 264.The bushings 279 are held in place by a bolt 286-and-nut 287 assembly,wherein the bolt extends through openings (not identified) formed in thebushings, and the nut is seated in one of the bushings. A spacer 277 isdisposed around the bolt 286 between the bushings 279 to prevent bolt286 from being compressed to the point where the bushings 279 arecompressed.

Bushings 279 are formed with a cut 280 and the bushings are seated incomplementary D-shaped counterbores 275 to prevent the bushings fromrotating. It is anticipated that the inside walls of bushings 279 willbe formed to conform with the outside walls of nuts 287 to prevent thenuts from rotating. In some preferred embodiments of the invention, nuts287 will have rounded heads adapted to receive an Allen wrench. Bolts286 are of a length so that their heads will be located inside theassociated bushings 279 when the fastening assemblies 278 are puttogether.

Lower linkage member 254 is pivotally secured to the mounting block tabs276 by a pivot pin 292, as depicted in FIG. 13B. Pivot pin 292 is atube-shaped pin that extends through concentric openings formed in thetabs 276 and through the passageway defined by the adjacent lowerlinkage member sleeve 270. Washers 293 are disposed over the exposedends of the pivot pins 292. In some preferred embodiments of theinvention, the ends of the pivot pin 292 used to secure the lowerlinkage member 254 to mounting block 256 are bent over onto the mountingblock tabs 276 to permanently secure the pin in place. The pivot pin 292used to secure lower linkage member 254 to handlebar clamp 258 isreleasably secured in place by a flat, C-shaped retaining ring 291, asdescribed hereinafter.

Handlebar clamp 258, as seen in FIGS. 10 and 11, has a main body 294 inthe shape of elongated split O-ring similar to the main body 40 of thefirst described handlebar clamp 22 (FIG. 2). A pair of parallel,spaced-apart tabs 296 formed integrally with the main body 294 extendtoward the mounting block 256. Upper linkage member 252 is pivotallyattached to the handlebar clamp 258 by a fastening assembly 278. Thebushings 279 and bolt 286 of the assembly extend through openings (notidentified) in the tabs 296 and into the passageway of the upper linkagemember sleeve 264. Lower linkage member 254 is secured to the handlebarclamp 258 by a pivot pin 292. Pivot pin 292 extends through concentricopenings formed in the tabs 296 and through the passageway in thelinkage member sleeve 270. Pivot pin 292 is releasably secured to thehandlebar clamp 258 by retaining ring 291, which is disposed against theadjacent tab 296. Pivot pin 292 may be formed with a groove 289 tofacilitate the interconnection of retaining ring 291.

One end of the spring 260 is held in place by a pivoting spring seat 298that is disposed against the lower linkage member sleeve 270 adjacentthe mounting block 256. Spring seat 298 is formed from a single piece ofnylon or other low-friction material. The spring seat has a base 300from which three parallel ribs 302 extend. Ribs 302 are formed withexposed faces 304 distal from the base 300, which has a concave profile.The profile of the rib faces 302 conforms to the outer curvature of theadjacent sleeve 270 so that the spring seat 298 can be fitted againstthe sleeve. A round protrusion 299 extends above the spring seat base300. The diameters of the spring seat base 300 and protrusion 299 areselected so that the spring 260 can be fitted over the protrusion andrest against the base.

The opposed end of the spring 260 is disposed against the stop assembly262. The stop assembly consists of a three-sided bracket 308 thatextends down from the upper linkage member 252 adjacent the handlebarclamp 258. Bracket 308 is positioned so that the sides thereof areparallel to the longitudinal axis of the upper linkage member 252 andthe center section thereof extends across the linkage member. It will beunderstood that, while bracket 308 is shown in fixed relation to upperlinkage members 252, bracket 308 may also be formed to be adjustablelongitudinally. The movement of bracket 308 toward the from fork stem 12will allow the handlebars to be raised upwardly in their staticposition. The center section of bracket 308 is provided with an openingover which a threaded ring 312 is secured. A set screw 314 is disposedin the opening and is adjustably held in place by the threaded ring 312.Set screw 314 has a rounded tip against which a metal spring seat 316 isdisposed. Spring seat 316 has a circular base 317 formed with a concaveindentation 318 (shown in phantom) so that the seat can be disposed overthe tip of the set screw 314. A cylindrical boss 320 extends above theopposed side of the spring seat base 317. Spring seat base 317 and boss320 are dimensioned so that spring 260 extends over the boss and restsagainst the base. Both spring seats 298 and 316 are held in place by theoutward expansion of the opposed ends of spring 260.

The sides of bracket 308 slope downward toward the adjacent end of theupper linkage member 252. The sides of the bracket 308 are furtherformed with concave indentations 322 to keep the bracket spaced from theadjacent lower linkage member sleeve 270. A pad 324 formed of rubber orother compressible elastomeric material is fitted over set screw 314between the sides of the bracket 308. The opening in the pad 324 throughwhich the set screw 314 passes is dimensioned to have a relatively tightfit around the screw. The pad 324 normally abuts the adjacent lowerlinkage member sleeve 270.

The handlebar assembly 250 of this embodiment of the invention isarranged so that a spring 260 normally exerts a biasing, or preload,force against both the spring seat 298 disposed against the lowerlinkage member sleeve 270, and against the spring seat 316 that isdisposed against the stop assembly 262. Set screw 314 allows the overallstatic bias, the static-state spring expansion, to be adjusted for thepreference of the cyclist. When a cyclist is exposed to a jolt or bumpand pushes downward on the handlebars 24, linkage members 252 and 254pivot downward. A fraction of the energy imparted to the handlebars bythe cyclist is absorbed by the downward movement of the assembly 250.During this downward movement, the stop assembly 262 moves toward theopposed spring seat 298, which, along with spring 260 is pivotingdownward with the rest of the assembly, to further compress the spring260. Upon release of the downward force by the cyclist, the spring 260is able to expand to urge the assembly 250 upward. The upward movementof the assembly 250 is stopped by the abutment of the stop pad 324against the lower linkage member sleeve 270.

Spring 260 of this assembly 250 of the invention extends horizontallyalong a significant portion of the length of the lower linkage member254. Consequently, the spring has a relatively long length over which itcan be compressed, as opposed to springs that are merely disposedbetween the upper and lower linkage members. As a result, the spring canbe significantly more flexible than those that would otherwise extendgenerally vertically between the linkage members. This enhances theassembly 250's ability to attenuate the road shock, which wouldotherwise be transferred to the cyclist. Moreover, spring 260 extendsbetween two easily accessible points in the assembly 250, between thelower pivot point of the mounting block 256 and the stop assembly 262.As a result, the spring can readily be inserted in place during themanufacture or maintenance of the assembly 250.

Stop assembly pad 324 provides a cushioned stop to the upward movementof the assembly 250. Moreover, the static angle of the assembly can bereadily modified by simply changing the thickness of the pad 324 usedwith the assembly; relatively thick pads can be coupled to the assemblywhen it is desired to have a relatively small angle between the assemblyand the horizontal, and relatively thin pads can be used when it isdesired to increase that angle. Furthermore, the stop pad serves to lockthe set screw 314 in place. This prevents the high-frequency vibrationsthat are invariably imparted to the assembly 250 from working the setscrew 314 free from the position to which it has been preset.

Still another advantage of this assembly is that the spring ispositioned to minimize sliding friction. This enhances the overallflexibility of the assembly to further reduce the mechanical shock towhich the cyclist would otherwise be exposed. Also, the interfacebetween the stop assembly 262 and the adjacent lower linkage membersleeve 270 is located between the sidewalls 266 of the lower linkagemember. The lower linkage member 254 thus serves to cover up a pinchpoint in which either an article of the cyclist's clothing or part ofthe cyclist's body could otherwise become caught.

FIGS. 14-16 illustrate an alternative assembly 330 of this inventionspecially adapted for use with a touring bicycle. Assembly 330 includesan upper linkage member 332 and a lower linkage member 334, both ofwhich have generally rectangular cross-sectional profiles. Linkagemembers 332 and 334 are attached to a mounting block 336 fitted over thehead of the front fork stem 12. The ends of the linkage members 332 and334 distal from the mounting block 336 are attached to handlebar clamp338 to which the handlebars 24 are attached. A spring 340 extendsdiagonally between the linkage members 332 and 334.

Mounting block 336 is in the form of a cap provided with an opening 335for receiving a conventional expander bolt (not illustrated) forsecuring the block to the front fork stem 12. Alternatively, adhesivesmay be used either with or without conventional fastening elements tosecure the mounting block 336 to the threaded front fork stem. A pair ofrounded ribs 341 extend laterally across the front of the mounting block336 and are formed with bores 342 designed to receive hardware forattaching the linkage members 332 and 334 thereto. Handlebar clamp 338is in the form of a one-piece structure that has a main body 346 similarto that in the previously described handlebar clamp 22 (FIG. 2). Afirst, upper pillar 348 and a second, lower pillar 350 are both formedintegrally with a clamp main body 346. Both pillars 348 and 350 areformed with bores 351 designed to accept hardware for pivotally mountingthe linkage members 332 and 334 thereto. In the illustrated embodimentof the invention, the lower pillar 350 is shaped so that the bore 351associated therewith is located farther away from the center of theclamp main body 346 than the bore 351 of upper pillar 348. In otherembodiments of the invention, handlebar clamp 338 may be formed so thatpillars 348 and 350 have different positions relative to the axis of themain body 346 to allow for different positioning of the handlebars 24.

Upper linkage member 332 is formed of a single piece of metal that isshaped to have a top plate 354 and a pair of side plates 356 extendingdownward from the top plate 354. In one preferred embodiment of theinvention, upper linkage member 332 has a tapered profile such that itis narrow in the center and relatively wide on the ends that areattached to mounting block 336 and handlebar clamp 338. A set of threestiffening ribs 358 extend laterally across the inside of upper linkagemember 332 between the side plates 356 adjacent mounting block 336.Stiffening rib 358 located closest to mounting block 332 is the longestof the three ribs. Stiffening rib 358 located farthest from the mountingblock is the shortest of the three ribs, and the rib locatedtherebetween is of intermediate length. The decreasing length of theribs 358 ensures that the spring 340, when compressed, will not contactor otherwise abut the ribs. Upper linkage member 332 is further formedto include a threaded bore 360 located adjacent the point at which themember is attached to the handlebar clamp 338. Threaded bore 360 isoriented downward such that it is directed toward the point where thelower linkage member 334 is pivotally attached to the mounting block336. Upper linkage member 332 further includes a tab 359 that extendsdownward from the portion of the member that defines the rearwardsection of the bore 360. The upper linkage member 332 is positioned sothat at one end the member side plates 356 are fitted over the uppermounting block rib 341 and at the opposed end are fitted over the upperhandlebar clamp pillar 348.

Lower linkage member 334 is formed of a single piece of metal andincludes a base plate 361 to which two side plates 362 are attachedalong the longitudinal edges thereof. Base plate 361 includes a firstsection 364 located adjacent the mounting block 336, which extendsacross the lower edges of the side plates 362 and a second section 366that extends diagonally upward from the first section in the generaldirection of the handlebar clamp upper pillar 348. The base plate secondsection 366 terminates at the top edge of the side plates 362 and meetswith a front plate 368. Front plate 368 is a generally L-shaped memberthat includes a tab 370 that extends above the linkage member sideplates. The portion of the front plate 368 that extends below the tab370 curves forward such that the lower portion of the plate extendsacross the opposed lower edges of the side plates. Lower linkage member334 is further formed with three stiffening ribs 372 that extend acrossthe side plates 362 between the base plate second section 366 and thelower edges of the side plates. The lower linkage member is positionedso that, at one end, the side plates 362 are fitted over the lower ofthe mounting block ribs 341 and at the other end are fitted over thelower handlebar clamp pillar 350.

Linkage members 332 and 334 are pivotally connected to the mountingblock 336 and the handlebar clamp 338 by fastening assemblies 376, oneshown in detail in FIG. 16. Each fastening assembly 376 includes atubular sleeve 378 that is fitted into either a bore 342 or 351, ofeither the mounting block 336 or the handlebar clamp 338. The sleeve 378also extends through a pair of concentric openings 380, one openingshown, formed in the linkage member side plate 356 or 362 with which thesleeve is associated. FIG. 17 depicts how upper linkage member 332 isconnected to handlebar clamp upper pillar 348. Bushings 382, formed ofTeflon, bronze, or other low-friction material, are disposed over theopposed ends of the sleeve 378 between the sleeve and the adjacentsections of the linkage member side plates 356 or 362 that define theopenings 380. Each bushing 382 is formed with an annular flange 384. Thebushings 382 are arranged so that the flanges 384 are disposed betweenthe mounting-block ribs 341 or the handlebar clamp pillars 348 or 350,and the adjacent linkage member side plates 356 or 362. A button-headscrew 386 is fitted over the exposed ends of each sleeve 378. A washer388 formed of Teflon, Nylon, or other low-friction material, is firedover the head of each screw 386 such that the washer is located betweenthe screw and the adjacent linkage member side plate 356 or 362.

A spring seat 392, substantially identical to the previously describedlow-friction spring seat 298 (FIG. 10), is used to mate one end ofspring 340 with the sleeve 378 used to interconnect lower linkage member334 to mounting block 336. The opposite end of spring 340 is fitted overa metallic spring seat 394 substantially identical to the spring seat316 of the previously described embodiment of the invention. Spring seat394 is held in place by a set screw 395 secured in threaded bore 360. Acap 397, having the shape of an elongated U and formed of compressibleelastomeric material, is fitted over the tab 370 that extends upwardfrom lower linkage member 334.

When the assembly 330 of this embodiment of the invention is installedon a bicycle, the preload compression of the spring 340 maintains theassembly and handlebars 24 in their normal, upright, static position.Both spring seats 392 and 394 are also held in place by the normal,static, expansion of the spring 340. When the cyclist exerts a downwardforce on the handlebars 24, the linkage members 332 and 334 pivot theassembly and handlebars downward. Downward movement of the assembly 330urges the adjacent metallic spring seat toward the static spring seat tofurther compress the spring 340. Upon release of the downward force bythe cyclist, the spring 340 returns the assembly to the initialposition. The upward movement of the assembly is stopped by the actionof the upper linkage member tab 359 abutting the cap attached over thelower linkage member tab 370.

The stiffening ribs of this embodiment of the invention provide lateralstrengthening of the linkage members 332 and 334. Consequently, thisassembly is well suited to withstand lateral stress that a cyclist mayimpose on the assembly due to uneven stresses that a cyclist imposes onthe handlebars 24 during riding. The stop or static angle of assembly330 of this embodiment of the invention can be adjusted by fitting caps397 having different overall widths over tab 370. Caps 397 havingrelatively wide walls can be installed in the assembly 330 so that thelinkage members 332 and 334 are positioned relatively horizontally; capswith relatively thinner walls can be fitted over the tab when it isdesirable to set the assembly so that the linkage members and thehandlebars 24 are located in a more upwardly oriented position.Moreover, lower linkage member tab 370 extends into the space betweenthe upper linkage member side plates 356 before striking thecomplementary upper linkage member tab 359. Thus, the stop mechanism ofthis embodiment does not create an exposed pinch point.

Still another feature of this embodiment of the invention is that thelinkage members 332 and 334 can be molded of aluminum or otherlightweight material. This serves to reduce the overall weight of theassembly 330. Moreover, the linkage members can be formed intoaesthetically pleasing shapes by the molding process.

FIGS. 18-20 illustrate another embodiment of a handlebar assembly 400 ofthis invention. Assembly 400 includes an upper linkage member 402, apair of spaced-apart, parallel lower linkage members 404, a mountingblock 406, and a handlebar clamp 408. A spring 410 is disposed betweenthe lower linkage members 404. Spring 410 extends between a down-stop412 pivotally mounted to the mounting block 406 and an up-stop assembly414 formed integrally with the upper linkage member 402, which extendsbetween the lower linkage members 404.

Mounting block 406 consists of a tubular female adapter 416 dimensionedto be secured over the head of the bicycle front stem 12. A pair ofparallel, spaced-apart mounting flanges 418 extend outward from thefemale adapter 416. Handlebar clamp 408 includes a main body 420substantially identical to the main body 40 of the first describedhandlebar clamp 22 (FIG. 2). A pair of parallel, spaced-apart flanges422 extend rearward from the opposed ends of the handlebar clamp mainbody 420. Both the mounting block flanges 418 and the handlebar clampflanges 422 are formed with openings (not identified) to facilitate thecoupling of hardware for mounting the linkage members 402 and 404thereto.

Upper linkage member 402 is a cylindrical aluminum tube that, in theillustrated embodiment of the invention, has an oval cross-sectionalprofile. Cylindrical mounting sleeves 424 are attached to each end ofupper linkage member 402 such that the sleeves extend transversely, orlaterally, across the opposed ends of the member. The lower linkagemembers 404 consist of solid aluminum bars that extend between mountingblock 406 and the handlebar clamp 408. In the depicted embodiment of theinvention, the lower linkage members 404 are each formed with a groove428 along the outer surface thereof. The grooves 428 serve to reduce theoverall weight of the lower linkage members 404 and of the assembly 400.The ends of the lower linkage members 404 are formed with openings 405to facilitate the insertion of mounting hardware. Assembly 400 isarranged so that both the upper linkage member 402 and the lower linkagemembers 404 are mounted between the mounting block flanges 418 and thehandlebar clamp flanges 422.

FIG. 18A depicts in detail one of the fastening assemblies 429 used tosecure the linkage members 402 and 404 to the mounting block 406 and thehandlebar clamp 408. FIG. 18A specifically depicts how a fasteningassembly 429 is used to secure the upper linkage member 402 to themounting block 406. Fastening assembly 429 includes a bolt 430 thatextends through the openings formed in the mounting block flanges 418and the upper linkage member sleeve 424. An internal bushing 431 iswelded, soldered, or otherwise permanently secured to each end of theupper linkage member sleeve 424. Each bushing 431 has a flange 431a thatis disposed around the outside of the sleeve 424, a female taperedsection 431b that extends into the sleeve, and a tubular section 431cthat is located inside of the sleeve. The sleeve 424 is formed with acounterbore (not identified) to facilitate the mating of the bushings431 thereto. In some preferred embodiments of the invention bushings 431are formed of steel.

First and second external bushings, 435 and 436, respectively, arefitted over the opposed mounting block flange 418 openings and extendinto the sleeve 424. First external bushing 435 has a flange 435a thatis disposed against the mounting block flange 418, a first inwardlytapered section 435b that extends into the flange opening, a tubularsection 435c that extends to the inside surface of the flange, and asecond inwardly tapered section 435d that extends into the sleeve 424.Second external bushing 436 has a flange 436a that is disposed againstthe mounting block flange 418, an intermediate tubular section 436b thatextends through the flange, and an inwardly tapered section 436c thatextends into the sleeve 424. The inside of the second external bushingis further provided with threading (not identified) to facilitatesecuring the bolt 430 thereto. External bushings 435 and 436 are formedof bronze, brass, or other material that has a low coefficient offriction. External bushings 435 and 436 are formed so that outersurfaces of the first external bushing second tapered section 435d andof the second external bushing tapered section 436c are identical indimension to the inner surfaces of the adjacent internal bushing taperedsections 431b.

When this embodiment of the invention is assembled, the bolt 430 ispassed through the bushings 431, 435, and 436 and is secured by thecomplementary threading of the second external bushing 436. The head ofthe bolt 430 is disposed in the space defined by the first externalbushing first tapered section 435b. As the bolt 430 is tightened,mounting block flanges 418 are urged toward the upper linkage membersleeve 424 so that the first bushing second tapered section 435d and thesecond external bushing tapered section 436c are urged into contact withthe adjacent internal bushing tapered sections 431c. The fasteningassembly 429 thus functions as an adjustable damping mechanism that usesthe friction that is developed along the internal bushing/externalbushing interface to slow the pivoting movement of the linkage member402.

The spring down-stop 412, as depicted in FIG. 19, is a single-piece unitformed of nylon or other low-friction material that extends around thepivot pin 430, and is used to mate the lower linkage members 404 to themounting block 406. The down-stop 412 has a generally tube-shaped body433, which is disposed about the fastening assembly 429 and serves tokeep the linkage members 404 spaced apart. A protrusion 440 defines agenerally circular surface and extends outward from one section of thebody 433. A small cylindrical boss 442 extends outward from the centerof the protrusion 440. The diameters of the protrusion 440 and the boss442 are selected so that the spring 410 can be fitted over the boss andrest against the outer surface of the protrusion.

The spring up-stop assembly 414 consists of a mounting bracket 446welded or otherwise permanently secured to the undersurface of the upperlinkage member 402 adjacent handlebar clamp 408. Bracket 446 includes asolid finger 448, which extends perpendicularly downward from the upperlinkage member 402. Finger 448 is formed with a threaded bore 452adapted to receive a set screw 454. Spring 410 abuts a metallic springstop 456 that is held in place by the set screw 454 adjacent the finger448. Spring stop 456 is formed of a single piece of metal and has ashape that approximates a slice through a cone. The tip or narrow end ofthe spring stop 456 is formed with a recess 457 such that the end can befitted over the tip of the set screw 454. A cylindrical boss 460 extendsoutward from the center of the opposite surface of the spring stop 456.Spring stop 456 and boss 460 are dimensioned so that spring 410 extendsaround the boss and rests against the adjacent surface of the stop.

An elastomeric plug 451 is disposed inside the coil spring 410 betweenthe down-stop 412 and the spring stop 456. The plug 451, which floats inposition, serves as a cushioning member to prevent the overcompressionof the spring 410 in the event the linkage members 402 and 404 areforced excessively downward.

Bracket 446 further includes an extended section 462 that extendsgenerally perpendicularly from the finger 448 toward the handlebar clamp408. The bracket 446 is shaped so that extended section 462 defines anouter surface that has a slope that tapers toward the end of the upperlinkage member 402. In other words, the extension section 462 isrelatively wide adjacent the finger 448, but narrower adjacent the endof the upper linkage member 402. The end of the extended section 462adjacent the end of the linkage member 402 is formed with a cutout 458in which a plastic button 459 is secured. The button 459 has a slopeidentical to that of the bracket's extended section 462. A sleeve 464 isfitted over the fastening assembly 429 that couples the lower linkagemembers 404 to the handlebar clamp 408. The sleeve 464 abuts the surfaceof the bracket's extended section 462 to stop the upward movement of theassembly 400. The sleeve 464 also serves to keep the lower linkagemembers 404 spaced apart.

When a downward force is exerted on the handlebar assembly 400 of thisembodiment of the invention, linkage members 402 and 404 are pivoteddownward. The up-stop assembly 414 is pivoted toward the down-stopassembly 412 to compress the spring 410 therebetween. Upon release ofthe downward force, spring 410 is able to expand to move the linkagemembers 402 and 404 and handlebar 24 upward. Upward movement of theassembly 400 is stopped by the action of the pivot pin 426 abutting thesloping surface of the mounting bracket's extended section 462. Anadvantage of this assembly is that the flexibility of the linkagemembers 402 and 404 can be set by adjusting the fastening assemblies429. The static angle of assembly 400 could be readily changed by simplyfitting sleeves 464 of different outer diameters over the pivot pin 426.A large-diameter sleeve 464 can be installed when the cyclist desiresonly minimal up-angle for the assembly 400 and handlebars; when a largerup-angle is desired, a sleeve having a smaller outside diameter can beinstalled. The relative soft surface of the button 429 serves to dampthe actual stopping movement of the assembly 400 when the sleeve 464strikes the bracket's extended section 462.

In still other versions of the handlebar assembly of this invention, itmay be desirable to provide the assembly with two or more dampingmembers, each designed to withstand a particular form of mechanicalshock. For example, FIG. 21 depicts an alternative version of theassembly 250, wherein, instead of a single spring 260 (FIG. 10), twoseries-connected coil springs 470 and 472 extend between the opposedspring seats 298 and 316. Springs 470 and 472 are held together by a setof clamps 474 and are wrapped around the portions of the springs thatinterface. In this embodiment of the invention, spring 470, the springadjacent the mounting block 256, is a relatively stiff spring. Spring472, the spring adjacent handlebar clamp 258, is significantly moreflexible. An advantage of this embodiment of the invention is thatspring 472, the more flexible spring, has more give to be able to absorbthe continuous white noise, road noise, the small vibrations, that thecyclist is continually exposed to. Spring 470 will flex, or give, toabsorb the lower frequency, higher amplitude vibrations that the cyclistis exposed to when passing over bumps or other significant road flaws.It should be understood that the depicted clamps 474 are merely onemeans for mating the two springs 470 and 472 together; other couplingassemblies may, of course, be employed to accomplish the same task. Forexample, it may be desirable to mate the springs 470 and 472 to adouble-headed spring seat, not illustrated.

The same advantage can be obtained by fitting an elastomeric plug 478 inthe spring 260 between the spring seats 298 and 316 as depicted in FIG.22. In this embodiment of the invention, it is anticipated that thespring will be selected so that it is suited for absorbinghigh-frequency vibrations while the elastomeric plug will serve to dampthose of low frequency. It is understood that, in alternative versionsof this embodiment of the invention, the particular vibrations that eachdamping member is intended to absorb can be reversed. Still otherversions of the invention may employ two spaced-apart elastomeric plugsthat come together when the handlebar assembly of this invention isurged downward. Moreover, in still other embodiments of the invention,it may be desirable to use the spring 250 in combination with anotherdamping member, such as a piston 482 or other fluid-based dampingdevice, as depicted in FIG. 23. Again, it is anticipated that, in mostconstructions of this invention, the spring will serve to damp thehigher frequency vibrations while the piston 482 will damp those of lowfrequency. When either the elastomeric plug 478 or piston 482 isinstalled in the assembly of this invention, it is anticipated that theywill be compression-fitted into place. Alternatively, the elastomericplug 478 may be secured in place by adhesive, and the piston 482 may besecured in place by threaded fasteners and the like. Moreover, thesecomponents may be disposed in locations other than along the center axisof the spring 260.

FIGS. 24 and 25 illustrate another handlebar assembly 490 of thisinvention. Handlebar assembly 490 includes a mounting block 256a and ahandlebar clamp 258a similar to those described with respect to theversion of the invention depicted by FIG. 10. A lower linkage member 492and an upper linkage member 494 are both pivotally attached to themounting block 256a and the handlebar clamp 258a. Downward movement ofhandlebar assembly 490 is damped and upward movement of the assembly islimited by a coupling assembly 495 that extends between the end of thelower linkage member 492 attached to the mounting block 256a and the endof the upper linkage member 494 attached to the handlebar clamp 258a.Coupling assembly 495 also limits the downward movement of the handlebarassembly 490 and of the handlebars 24 (FIG. 1) attached thereto.

Each linkage member 492 and 494 comprises a single piece of metal shapedto have three walls, a base and two spaced-apart sidewalls that extendoutward from the base to give the member a generally U-shaped profile.The linkage members 492 and 494 are arranged so their open ends areadjacent each other. The previously described pins 292 (FIG. 13B) orother suitable means may be used to pivotally couple the linkage members492 and 494 to the mounting block 256a and the handlebar clamp 258a. Thesides of the linkage members 492 and 494 are formed with openings (notidentified) to facilitate the insertion of pivot pins therethrough.

Coupling assembly 495 includes a first spring seat 498 adjacent themounting block 256a and a second spring seat 500 adjacent the handlebarclamp 258a. Both spring seats 498 and 500 are formed of metal orplastic. The first spring seat 498 has a relatively wide, generallyrectangular base 502 from which a small, cylindrical boss 504 extendslongitudinally outward. A laterally extending opening 506 is formed inthe end of base 502 distal from boss 504 to facilitate the pivotalmounting of the first spring seat 498 to the mounting block 256a by thesame pivot pin that couples the lower linkage member 492 to the mountingblock. The end of the base 502 adjacent the opening 506 has asemicircular profile to maximize the sweep of first spring seat 498about the mounting block 256a. The second spring seat 500 has a base 508and a boss 510 that are substantially identical to those elementsdescribed with respect to the first spring seat 498. Base 508 is formedwith a laterally extending opening distal from boss 510 to facilitatethe pivotal mounting of the second spring seat 500 to the handlebarclamp 258a.

Spring seats 498 and 500 are connected together by a bolt 512 and urgedapart by a spring 514. Bolt 512 extends through an axial bore 516 thatextends completely through the second spring seat 500 and is coupledinto an axial bore 518 that extends only partially through the firstspring seat 492. Bolt 512 has a head 519 that is seated in bore 516 anda shaft 520 with a threaded tip that adjustably interlocks withcomplementary threading around bore 518. Boss 506 is formed with aninwardly directed annular lip 522 that serves to define a neck opening(not identified) in the second spring seat 500 that has a smallerdiameter than the coaxial bore 516. The annular lip 522 is dimensionedso that second spring seat 500 can travel freely along the length of thebolt 512. Bolthead 519 is formed with a socket space (not illustrated)dimensioned for receiving a complementary fastening tool, such as anAllen wrench, to allow the selective positioning of the bolt 512 in bore518. A first rubber damping ting 526 is disposed about the bolt shaft520 between spring seats 498 and 500. A second rubber damping ring 528is seated around the portion of the shaft 520 disposed in bore 516between bolthead 519 and the inside of the lip 522. Spring 514 is a coilspring, the opposed ends of which are disposed about the spring seatbosses 504 and 510. Spring 514 has an inner diameter larger than theouter diameter of the first damping ring 528; this prevents the springfrom catching on the damping ring when the spring is compressed.

When a downward force is imposed on a set of handlebars 24 (FIG. 1)attached to a bicycle by way of this assembly 490, linkage members 492and 494 pivot downward to cause a downward, pantograph motion of thehandlebars. The opposed spring seats 498 and 500 are urged together tocompress spring 514. The compression of spring 514 slows the downwardmovement of both the linkage members 492 and the handlebars 494. If thelinkage members 492 and 494 pivot downward a sufficient degree, theirmovement, and the movement of the handlebars 24, will be stopped by thecompression of the first damping ring 526 between the spring seats 498and 500. The compressible properties of damping ring 526 serve to slowthe rate at which the linkage members 492 and 494 decelerate to minimizethe physical shock of the stop to which a cyclist would otherwise beexposed.

Upon release of the downward force on the handlebars 24, spring 514expands to its static position to cause upward movement of the linkagemembers 492 and 494 and the handlebars. The upward movement of thehandlebar assembly 490 and the handlebars 24 is stopped by thecompression of the second damping ring 528 between the bolthead 519 andthe annular lip 522 of boss 510. Since damping ring 528 is initiallycompressed before the second spring seat 500 comes to a complete stop,the cyclist is not subjected to a significant mechanical shock as aconsequence of the handlebars 24 reaching their upwardmost position.

An alternative handlebar assembly 540 that can be selectively placed inand out of the shock-absorbing mode is depicted in FIGS. 26-28.Handlebar assembly 540 includes a mounting block, head unit 542 that isattached to a stem, quill 544, that is coupled to the front fork of thebicycle with which the assembly 540 is used. Assembly 540 includes asingle upper linkage member 546. A pair of parallel, spaced-apart, lowerlinkage arms 548 serve as a lower linkage member. The upper linkagemember 546 and the linkage arms 548 are pivotally connected at one endto the head unit 542. The distal, forward, ends of the upper linkagemember 546 and linkage arms 548 are pivotally connected to a handlebarclamp 550 to which the handlebars 24 are secured. A spring 547 thatextends between the head unit 542 and the handlebar clamp 550 damps thedownward movement of the linkage elements 546 and 548. A lockout arm 552is pivotally connected to the forward end of one of the linkage arms548. The free end of the lockout arm 552 can be selectively coupled tothe end of the upper linkage member 546 attached to the head unit 542 toprevent the pivoting of assembly 540 to lock out, restrict, itsshock-absorbing capabilities.

Linkage member 546 is in the form of a hollow, elongated body with agenerally oval profile. A pair of tubular sleeves 554 are secured acrossthe opposed ends of the upper linkage member 546 such that their axesextend laterally across the linkage member. Linkage arms 548 are in theform of elongated oval bars that are formed with openings 556 tofacilitate the mounting of the arms to the head unit 542 and handlebarclamp 550 as will be described hereinafter. The linkage arms 548 areformed with circular flanges 558 located around the openings 556 andthat extend inward such that the flanges on the opposed surfaces of thelinkage arms are directed toward each other.

Linkage member 546 and linkage arms 548 are secured to the head unit 542and handlebar clamp 550 by a set of metallic bearing pins 560 and 561.Specifically, a first pair of bearing pins 560 extend through openings562 formed in a forward directed head unit flange 564 and into theadjacent linkage member sleeve 554. A second pair of bearing pins 560extend through openings 566, formed in a rearward directed handlebarclamp flange 568 into the forward located linkage member sleeve 554. Afirst pair of bearing pins 561 are seated in a second pair of openings562 formed in the head unit flanges 564 and a second pair of bearingpins 561 are seated in a second pair of openings 566 formed in thehandlebar clamp flanges 568. Tubular-shaped pivot bushings 570, whichare seated in the linkage member sleeves 554 and in the openings 556formed in the ends of the lower linkage arms 548, provide a low-frictioninterface between the beating pins 560 and 561 and the linkage membersto which they are connected. The bushings 570 are formed of plastic andare shaped to have annular lips 572 around their outer edges tofacilitate their proper seating in the openings in which they aredisposed. In one version of the invention, bushings 570 are shaped sothat they define bores, having diameters slightly less than thediameters of the head unit openings 562 and handlebar clamp openings 566with which they are associated. In order to facilitate a snug fit of thebearing pins 560 and 561, the pins are formed with relativelylarge-diameter outer sections and smaller diameter inner sections,individual sections not identified.

Bearing pins 560, the bearing pins that secure the upper linkage member546 to the head unit 542 and the handlebar clamp 550, simply face eachother in the upper linkage member sleeves 554 in which they are seated.The beating pins 561 that secure the lower linkage arms 548 to the headunit 542 are seated in a head unit sleeve 574. The bearing pins 561 thatsecure the lower linkage arms 548 to the handlebar clamp 550 are seatedin a handlebar clamp sleeve 576. The head unit sleeve 574 is aring-shaped member that is located between the adjacent linkage armflanges 558. Handlebar clamp sleeve 576 is a metallic spool-shapedsleeve that is located between the linkage arm flanges 558. Tofacilitate the mating of the beating pins 561 to the head unit andhandlebar clamp sleeves 574 and 576, respectively, and to hold thesleeves in place, the bearing pins 561 are formed with small diameterring-shaped extensions 577. It is the ring-shaped extensions 577 thatare actually seated in the head unit and handlebar clamp sleeves 574 and576, respectively.

Bearing pins 560 and 561 are held in place by a set of beating bolts578. The bolts 578 have heads 579 that have a diameter such that theycan freely rotate inside the bearing pins 560 and 561. The bearing bolt578 that secures the upper linkage member 546 to the handlebar clamp 550is held in position by a conventional hex nut 580, which is seated inthe bearing pin 560, opposite the pin in which the bolthead 579 isseated. The hex nut 580 fits snugly in the bearing pin 560 in which itis seated. The other three bearing bolts 578 are held in place by customnuts that will be described hereinafter. The heads 579 of the bearingbolts 578 are provided with openings (not illustrated) to facilitatetheir rotation by Allen wrenches or other appropriate fastening tool. Toprevent the bearing pins 560 and 561 from rotating and, in turn,unscrewing the bearing bolts 578, the pins are formed with outwardlyextending lips 581 around their outer surfaces. The lips 581 define cuts582 that abut steps 583 formed in the head unit and handlebar clampflanges 564 and 568, respectively, to block movement of the bearing pins560 and 561.

Spring 547 is mounted to the head unit 542 by a spring seat 584 that isseated over the head unit sleeve 574. The opposed end of spring 547 iscoupled to a spring stop 586 that is attached to a bracket 588 mountedto the forward end of the upper linkage member 546. Bracket 588 is agenerally L-shaped bracket that is secured to the upper linkage member546 by welding or other suitable means. Spring stop 586 is coupled tobracket 588 by an adjustable tension screw 589. In some versions of theinvention, tension screw 589 is not threadably secured to the springstop 586. Rather, spring stop 586 is formed with a center bore 591 thathas a diameter larger than that of the tension screw 589. Bore 591 mayeven have a slightly outwardly tapered profile. Inside the base of thebore 591 is a roller beating 593. The tip of the tension screw 589 abutsthe roller beating 593. The roller beating 593 functions as alow-friction interface between the spring stop 586 and the tension screw589 that allows the spring stop to rotate without causing a looseningmotion in the screw.

A rubber up-stop 590 is fitted over the outer surface of the bracket588. The up-stop 590 is generally L-shaped such that it has a bootsection 587 that fits over the downwardly extending portion of thebracket 588 and a tongue 583 section that is generally parallel to theportion of the bracket that extends toward the handlebar clamp 550. Theup-stop 590 is provided with an opening (not identified) to facilitatethe securing of the tension screw 589 to the bracket 588. In someversions of the invention, the up-stop 590 is the actual part of thebracket assembly that contacts the handlebar clamp sleeve and adjacentlinkage arm flanges 558 to limit the upward movement of the handlebarassembly 540. Other versions of the invention are provided with adamping member 592 that is located adjacent the boot section 587 of theup-stop 590. The damping member 592 prevents shimming of the tensionscrew 589 and further serves as the member that abuts the adjacentlinkage arm flanges 558 to stop the movement of the assembly 540.

Lockout arm 552 is in the form of an elongated, flexible flat metal bar.One end of the lockout arm 552 is pivotally attached to one of thelinkage arms 548. The free end of the lockout arm is releasably attachedto the upper linkage member 546, and is provided with a smallrubber-coated handle 598 to facilitate its movement. The free end of thelockout arm 552 is also formed -with an opening 599 to facilitate itspositioning as will be described below. The lockout arm 552 is securedto the linkage arm 548 by a flathead nut 600 that holds the associatedbeating bolt 578 in place. The flathead nut 600 has a lower base sectionshaped like a conventional nut and a disk-shaped head. The lockout arm552 is sandwiched between two low-friction nonmetallic washers 602, oneof which is between the arm and the adjacent bearing pin 561, the otherof which is between the arm and the flathead nut 600.

The free end of the lockout 552 arm is normally seated in a neutralposition over a button-head nut 604 that is coupled to the beating bolt578 that holds the lower linkage arms 548 to the head unit 542. If thecyclist wishes to lockout, or inhibit the shock-absorbing capabilitiesof the lockout assembly 540, the lockout arm 552 is shifted and seatedover a button-head nut 608 that is coupled to the bearing bolt 578 thatsecures the upper linkage member 546 to the head unit 542. Thebutton-head nuts 604 and 608 are each formed with conventional nutbodies and protuberances that are dimensioned to extend away from thebeating pins 560 and 561 in which the nuts are seated. Button-head nut604 is dimensioned to be significantly smaller in diameter than thelockout arm opening 599 in which the nut is disposed. This allows thelockout arm 552, as well as the rest of the handlebar assembly 540, tofreely pivot in response to the vibrations to which the associatedbicycle may be exposed. The protruding portion of button-head nut 608has a diameter selected so that the nut fits snugly in the lockout armopening 599. When the lockout arm is fitted over the button-head nut606, the lockout arm 552 prevents the pivoting movement of the linkageelements 546 and 548.

The shock-absorbing assembly 540 of this embodiment of the inventiondamps the front-end vibrations to which the cyclist will otherwise beexposed in a manner similar to that described with respect to the otherembodiments of this invention. Whenever the cyclist is exposed to adownward moving force, the linkage elements 546 and 548 pivot downwardand the compression of the spring 547 absorbs the shock of the resultantmotion. After the force is released, the spring 547 forces the linkagemembers 546 and 548 upward until the movement is blocked by the actionof the up-stop 590 abutting the linkage arm flanges 558 and thehandlebar clamp sleeve 576. Since the spring stop 586 is not securelyfastened to the associated tension screw 589, the rotation of the stop,which inherently occurs as a result of the repeated compression andexpansion of the spring, does not cause a like loosening rotation of thescrew, which could cause change in the tension on the spring or the stopto fall out of position. Still another feature of this invention is thatthe handlebar clamp 550 can be fastened "upside-down" to the linkageelements 546 and 548. This allows the cyclist a choice in setting theposition of the handlebars.

Another feature of the assembly of this invention is that by selectivelypositioning the lockout arm 552, the cyclist can block out or inhibitthe shock-absorbing capabilities of the assembly as desired. Thus, forexample, when during the course of a ride, the cyclist decides it isdesirable to push off the handlebars to maximize the force applied tothe pedals, all that he needs to do is to pivot the lockout arm 552 fromthe neutral position to the lockout position over button-head nut 608.The lockout arm 552, once engaged in this position, prevents the linkagemembers 546 and 548 from pivoting. The cyclist can then push off thehandlebars 24 to increase the energy applied to the pedals. When theextra force is no longer desired, the cyclist can easily return theassembly 540 to its normal shock-absorbing mode of operation by simplymoving the lockout arm 552 from the lockout position to the neutralposition over button-head nut 604. Since the lockout arm handle 598faces the cyclist, relatively little mental effort or time is needed toshift the assembly from its normal mode of operation to the lockoutmode.

Another alternate embodiment of the invention will now be discussed withreference to FIGS. 30-32. A handlebar support assembly 700 is providedthat is adjustable to raise or lower the position of the handlebar.Support assembly 700 is similar in most respects to the embodimentillustrated in FIG. 18 and discussed above, except for the provision ofan eccentric bearing pin 738 and an adapted head pivot unit 706 tosecure upper linkage member 702.

Specifically, support assembly 700 includes an upper linkage member 702(a first linkage member), a pair of spaced-apart, parallel lower linkagemembers 704, head pivot unit 706, and a handlebar clamp 708. A spring710 (shown in FIGS. 32A-C) extends between lower linkage members 704 andis operatively connected between upper linkage member 702 and lowerlinkage members 704 to bias handlebar clamp 708 to an upwardmostposition. Spring 710 extends between a down-stop 712 pivotally mountedto head pivot unit 706 and an up-stop assembly 714 (a first stop member)fixedly attached to upper linkage member 702.

Head pivot unit 706 consists of a tubular female adapter 716 secured, inuse, to stem 12 of the head of the bicycle. A pair of parallel mountingflanges 718 project integrally from either side of adapter 716 towardlinkage members 702 and 704. The planar surfaces of mounting flanges 718are also parallel to the axis of stem 12. Each flange 718 includes anupper mounting hole 719 and a lower mounting hole 721. Upper mountingholes 719 are laterally aligned, as are lower mounting holes 721, suchthat fasteners may be secured through them as explained below. Thediameter of upper mounting hole 719 is preferably somewhat larger thanthat of lower mounting hole 721. The diameter of upper mounting hole 719tapers inwardly.

Handlebar clamp 708 is substantially similar to that illustrated in FIG.18. Clamp 708 includes a main body 720, a pair of parallel, spaced-apartflanges 722, and openings (not identified) to facilitate the coupling ofhardware for mounting the linkage members 702 and 704 thereto.

Upper and lower linkage members 702 and 704 are also substantiallysimilar to those shown in FIG. 18 and discussed above. Upper linkagemember 702 is tubular with an oval cross section fixedly attached at theends to mounting sleeves 724. Mounting sleeves 724 are cylindrical andhave longitudinal axes transverse to the longitudinal axis of upperlinkage member 702, preferably perpendicular to stem 12. Preferably,plastic bearing sleeves 737 are fitted within both ends of mountingsleeves 724. Bearing sleeves 737 are cylindrical and have small outerflanges.

Lower linkage members 704 are bars with rectangular cross sections,preferably the same length as upper linkage 702, that extend beneathupper linkage 702. Lower linkage members 704 have holes at theirrearward ends for pivotal attachment to lower mounting holes 721 on headpivot unit 706. Bearing sleeves 739 are fitted through the rearwardholes in linkage members 704. Bearing sleeves 739 are similar to thosefitted within mounting sleeves 724. The forward ends of lower linkagemembers 704 are pivotally attached to handlebar clamp 708. Supportassembly 700 is arranged so that both upper and lower linkage members702 and 704 are mounted between head unit flanges 718 and handlebarclamp flanges 722.

Lower linkage members 704 are attached to head pivot unit 706 with abolt 730, extending through bushings 735 and 736, and secured with a nut732. Bushings 735 and 736 extend through flanges 718 and into bearingsleeves 739. Bolt 730 is threaded at one end to engage nut 732 andincludes a head at the opposite end with a hexagonal recess. Bushings735 and 736 are generally cylindrical with flanges on their outer ends.Bushings 735 and 736 fit within lower mounting holes 721. Bushing 735includes a recess within the outer end of the flange to receive the headof bolt 730. Bushing 736 includes a hexagonal recess to engaginglyreceive nut 732 and prevent it from rotating. Lower bolt 730 extendsthrough bushing 735 within lower mounting hole 721, left lower linkagemember 704, bearing sleeves 739 within downstop 712, right lower linkagemember 704, and bushing 736 to engage with nut 732.

Upper linkage member 702 is pivotally secured to head pivot unit 706 byengagement of rearward mounting sleeve 724 with bearing pins 738.Bearing pins 738 include pinheads 740, pin cylinders 742, bores 744, andrecesses 746. Pinheads 740 are disc shaped with a major portion of theirouter edge being tapered inwardly (FIG. 31). The outer portions ofpinheads 740 are preferably equal in diameter to the largest part of thetapered portions. The thickness of pinheads 740 is slightly greater thanthat of mounting flanges 718 with the tapered portion being slightlynarrower than mounting flanges 718. The diameter of pinheads 740 is suchthat the tapered portions engage within tapered upper mounting holes719.

Pinheads 740 preferably have circular cross sections. However, theyalternatively may be other geometric shapes that are movable withinmatching bores 744 into at least two positions for adjustment purposes.Providing disc-shaped pinheads 740 is preferred since such anarrangement allows for infinitely small adjustments.

Pin cylinders 742 are substantially smaller in diameter than pinheads740 and are eccentrically affixed to the inner surfaces of pinheads 740such that the longitudinal axes of pin cylinders 742 are parallel to thecenter axes of pinheads 740. The eccentric arrangement of pin cylinders742 relative to pinheads 740 allows pin cylinders 742 to be orientedwithin upper mounting holes 719 in an infinite number of positions byrotating pinheads 740 within mounting holes 719.

Bores 744 for receiving upper bolts 730 extend concentrically throughpin cylinders 742 and continue eccentrically through pinheads 740.Alternatively, bores 744 could extend eccentrically through pincylinders 742 and concentrically through pinheads 740. Pinheads 740 alsoinclude recesses 746, similar to the recesses described above withinbushings 735 and 736, for holding the head of bolt 730 and engagingupper nut 732.

Rearward mounting sleeve 724 is pivotally attached to pin cylinders 742with bearing sleeves 737 between rearward mounting sleeve 724 and pincylinders 742. By varying the position of pin cylinders 742 the angle(or rise) of linkage members 702 and 704 can be varied in infinitelysmall increments to position the height of the handlebar exactly aspreferred by the rider. For example, the rider may wish to slightlylower the handlebar for improved aerodynamics, or the rider may prefer amore upright riding position afforded by a raised handlebar for offroadriding.

FIGS. 32A-C illustrate three positions obtainable by orienting pincylinder 742 rearward, upward, and forward. The greatest rise isobtainable by orienting pin cylinder 742 rearwardly such that linkagemembers 702 and 704 are angled upwardly.

An intermediate position, illustrated in FIG. 32B is obtainable bypositioning pin cylinder 742 between extreme rearward and extremeforward positions. Note that with pin cylinder in the upward positionupper linkage member 702 is no longer parallel to lower linkage members704. However, the angle between linkages 702 and 704 is so slight thatvery little rotation of handlebar clamp 708 occurs when a shock isabsorbed and spring 710 is depressed. In the upward configurationillustrated in FIG. 32B the handlebar would only slightly rotate back asthe handlebar moves downwardly relative to stem 12.

The lowest position of handlebar clamp 708 is obtained with pin cylinder742 in a forward orientation. Note that in all three of theabove-described positions the spring depression or preload does notchange. Linkages 702 and 704, along with handlebar clamp 708, simplymove together with upstop 714 abutting sleeve 764 (a second stop member)in a static position.

As mentioned above, the microadjustability of the handlebar heightallows the rider to set a preferential height independent of stemadjustment. Stem adjustment may also be used in combination with thelinkage adjustment, described herein, to further increase the range ofadjustment. However, the adjustability of the support assembly makesprecise changes quick and easy. The upper bolt simply needs to beloosened, the pinhead rotated, for example, by applying a downward orupward force on handlebar clamp 708 and/or upper linkage member 702until in the desired position, and upper bolt 730 retightened. Taperedpinhead 740 securely locks pin cylinder 742 into position relative tohead pivot unit 706.

The foregoing description is for the purpose of illustration only.Alternative embodiments of this invention are possible without departingfrom the scope of the claims. For example, the depiction of the multipleopenings 94 at the tail end of the linkage members in the embodiment ofFIG. 4 and the use of the slides 170 in the embodiment illustrated inFIG. 8 are meant to be merely exemplary of how the adjustable handlebarassembly of this invention can be provided. Clearly, these features ofthe invention can be used with the other embodiments of the invention,and can be used together. Moreover, while the application discloses theuse of elastomeric material and leaf springs to damp the downwardmovement of the linkage members, these disclosures should by no means beconsidered limiting. For example, there may be instances where it isdesirable to place one or more coil springs between the upper and lowerlinkage members to damp both the downward and upward movement of theassembly.

It should further be understood that the various fastening assemblies278 and 376 and pivot pins 292 used to secure the linkage members to themounting blocks and/or handlebar clamps can be used with assembliesother than the ones with which they were described in thisspecification. Moreover, fastening assemblies 278 and 376 of thisinvention provide lightweight couplings that are formed from a minimalamount of parts that can readily be assembled and disassembled, and arenot unduly affected by normal environmental exposure. Thus, there may beinstances when it is desirable to use these assemblies 278 and 376 withother than the disclosed handlebar assemblies.

Some embodiments of the invention may include a spring unit locatedwithin the bicycle front fork assembly for damping the downward movementof the handlebar assembly. These assemblies may take the form of a setof bell-shaped washers that are connected to the upper linkage member bya cable. The downward movement of the assembly would serve to compressthe springs so that the springs contribute to the damping of themovement and the absorption of the downward force. Upon release of thedownward force, the springs would return to their original state tocause the upper and lower linkage members to likewise return to theirstatic state. These washers could further be provided with a set ofbell-shaped washers, which are oriented upward so that, when the linkagemembers are urged downward, the curved washers offer minimal resistanceand, when the springs start to return the linkage member to the staticstate, the washers offer substantially more resistance to damp theupward movement. Also, it should be noted that, in FIGS. 1-3, the lowerlinkage member 20 is shown as being pivotally connected to the mountingblock 16 in front of the front fork assembly stem 12; in the otherembodiments of the invention the lower linkage members are shownpivotally connected behind the stem. Neither of these depictions isintended as limiting. In fact, in other embodiments of the invention itmay be desirable to attach the upper linkage member to the bicycle sothat it is located forward of the front fork assembly stem 12. Moreover,assemblies other than those disclosed in FIGS. 9A and 9B may be used toattach the speedometer processing unit to the handlebar assembly of thisinvention. For instance, it may be desirable to arrange the fastenersthat are used to secure the cover of the speedometer processing unit 222so that they can be accessed only from the underside of the upperlinkage member. This would make it difficult for unauthorized persons toaccess the fasteners in order to remove the cover. Furthermore, itshould also be clear that the speedometer can be installed into theupper linkage members of other embodiments of this invention.

Also, while the upper and lower linkage members have been generallyshown as being parallel to each other, it should be understood that thisis simply for purpose of illustration and should not be construed aslimiting. In other embodiments of the invention, it may be desirable todesign the assembly so that the linkage members are not so aligned.Moreover, the fact that in the illustrated embodiments of the inventionthe upper and lower linkage members are shown as having generallyidentical lengths should not be considered limiting. An advantage ofhaving identical-length linkage members is that the assemblies and thehandlebars to which they are attached will move in a linear path. Inother embodiments of the invention, it may be desirable to arrange thelinkage members so that there is a slight curvature in the movement ofthe handlebar clamp and the handlebars attached thereto. This can beaccomplished by providing the handlebar assembly with upper and lowerlinkage members that are of uneven length.

It should also be recognized that the lockout arm 552 used to shift thehandlebar assembly in and out of the shock-absorbing mode of operationcan be used in other versions of the invention, different from the onewith which it is shown. In a similar vein, it should be recognized thatthere is no requirement that the lockout arm 52 always be pivotallysecured to one of the linkage arms 548 that serve as the lower linkagemember or that when in the lockout mode, it be secured to the upperlinkage member 546. In some versions of the invention it may bedesirable to pivotally secure the lockout arm 552 to the upper linkagemember 546, the mounting block 542, or even directly to the handlebarclamp 550. It is further possible to construct the assembly so that thelockout arm prevents the linkage members from moving when it is coupledto the arms 548 that function as the lower linkage member, the mountingblock 542, or the handlebar clamp 550. Furthermore, it may be desirableto provide the lockout arm 552 with multiple openings 610 as depicted inFIG. 29. Alternatively, the assembly could be provided with multiplestop members 608 for securing the lockout arm 552 in the lockout mode.An advantage of these versions of the assembly is that they make itpossible to lock out the movement of the linkage members in a number ofdifferent static positions. Thus, the cyclist could then lock out thehandlebars in one of a number of different positions in order to gainthe advantages or comfort of the selected position.

Therefore, it is the objective of the appended claims to cover all suchvariations and modifications as may come within the true spirit andscope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A bicycle handlebarsupport assembly for interconnection between a handlebar and a frontfork assembly, the support assembly comprising:(a) a head unit adaptedto be secured to the front fork assembly; (b) a first linkage memberhaving a front end, and a tail end wherein said tail end is pivotallyattached to said head unit; (c) handlebar clamp means for mounting thehandlebar attached to the front end of said first linkage member; (d) abiasing means, coupled to said first linkage member, for upwardlybiasing said handlebar clamp means; and (e) a first bearing pin coupledto said head unit and the tail end of said first linkage, said firstbearing pin being adapted for movement relative to said head unit tochange the position of said first linkage relative to said head unit,wherein said first bearing pin includes a pinhead engaged within a firstbore in said head unit and a first pin extension eccentrically attachedto said pinhead, said pin extension extending inwardly from said pinheadto engage the tail end of said first linkage, such that rotation of saidpinhead within the bore changes the position of the first pin extensionrelative to the head unit.
 2. The support assembly of claim 1, furthercomprising a second linkage member having a front end and a tail enddisposed adjacent said first linkage member and spaced therefrom, saidsecond linkage member being pivotally attached to said head unit at thetail end and attached to said handlebar clamp means at the front end,said first linkage member, said second linkage member, said head unit,and said handlebar clamp means forming a four-bar linkage assembly suchthat movement of said bearing pin to change the position of said firstlinkage member changes the height of said handlebar clamp means relativeto said head unit.
 3. The support assembly of claim 2, wherein saidfirst linkage member is disposed above said second linkage member. 4.The support assembly of claim 2, wherein said first linkage member isdisposed below said second linkage member.
 5. The support assembly ofclaim 2, wherein said pinhead is disc shaped with an outer taperedsurface, and wherein the first bore in said head unit is shaped toengage the tapered surface of said pinhead, the assembly furthercomprising a tightening means for securing said pinhead to said headunit such that the tapered surface of said pinhead is tightly heldwithin the first bore.
 6. The support assembly of claim 2, furthercomprising a second bearing pin coupled to said head unit and the tailend of said first linkage opposite said first bearing pin, said secondbeating pin being adapted for movement relative to said head unit tochange the position of said first linkage relative to said head unit,said second beating pin including a pinhead engaged within a second boreopposite said first bore in said head unit and a second pin extensioneccentrically attached to said pinhead, said second pin extensionextending inwardly from said pinhead toward said first pin extension toengage the tail end of said first linkage, such that rotation of saidpinheads within said bores changes the positions of the pin extensionsand thus, the tail end of the first linkage relative to the head unit.7. A bicycle handlebar support assembly for interconnection between ahandlebar and a front fork assembly, the support assembly comprising:(a)a head unit adapted to be secured to the front fork assembly; (b) anupper linkage member having a front end, and a tail end wherein saidtail end is pivotally attached to said head unit; (c) a lower linkagemember including two laterally spaced-apart longitudinally extendinglinkage arms located below said upper linkage member and spacedtherefrom, wherein said linkage arms are pivotally attached to said headunit; (d) handlebar clamp assembly means for mounting the handlebarpivotally attached to said upper linkage member front end, saidhandlebar clamp assembly also being pivotally attached to said linkagearms; (e) a stop assembly including a first stop member secured to saidupper linkage member adjacent said linkage arms and a second stop membersecured between said linkage arms, wherein said first stop member andsaid second stop member are positioned so that, when said upper linkagemember and said linkage arms of said lower linkage member are movedupwardly, said first stop member abuts said second stop member prior tosaid linkage arms contacting said upper linkage member; (f) a biasingmember coupled between one of said linkage members and said head unit;and (g) a bearing pin having a pinhead and an eccentrically mounted pinextension projecting inwardly from said pinhead, said pinhead beingmovably coupled to said head unit and said pin extension being coupledto the tail end of said upper linkage member for pivotally attachingsaid upper linkage member to said head unit.
 8. The support assembly ofclaim 7, wherein said linkage arms have a downstop member coupledbetween their tail ends, wherein said biasing member extends betweensaid first stop member and said downstop member.
 9. A bicycle handlebarsupport assembly for interconnection between a handlebar and a frontfork assembly, the support assembly comprising:(a) a head unit adaptedto be secured to the front fork assembly, said head unit including atleast one bearing pin having a pinhead and a pin cylinder extendinginwardly from said pinhead, said pin cylinder attached eccentrically tosaid pinhead; (b) a first linkage member having a front end and a tailend, wherein said tail end is pivotally attached to said head unit bybeing coupled to said pin cylinder; (c) a second linkage member having afront end and a tail end, wherein said tail end is pivotally attached tosaid head unit; and (d) a handlebar clamp pivotally attached to thefront end of said first linkage member and pivotally attached to thefront end of said second linkage member.
 10. The support assembly ofclaim 9, wherein said pinhead is disc shaped and includes a taperedouter surface, said head unit including a bore shaped to engage thetapered surface of said pinhead, said bearing pin further including atightening means for forcing the tapered surface of said pinhead intotight engagement with the bore.
 11. The support assembly of claim 9,further including a biasing means coupled to at least one of saidlinkage members for resisting downward forces on said handlebar clamprelative to said head unit.
 12. The support assembly of claim 11,wherein said first linkage member is disposed above said second linkagemember.
 13. The support assembly of claim 11, wherein said first linkagemember is disposed below said second linkage member.